Nad 352

[d7silver]

NAD 352 all four fuses blown. Can I ask if anyone has had this before, if so, what is the cure.
Thanks in advance.

[nigelwright7557]

Check for shorted output transistors.
Or possibly a fault in the power supply.

[burbeck]

hi
do you have any test kit?
if yes then go to plan C

if not then i would disconnect the amp from the mains, disconnect the speakers compleatly.
replace the fuses with the exact type as printed on the board (for instance Time lag 3.15, marked on the fuse as T3.15).

It is a matter of safety that the fuses are replaced by the exact types, please get the correct ones dont rush this proceedure.

Then looking at the fuses at arms lenth, reconnect the mains and switch on.

if the fuse or fuses blow again switch off imeadiatly, go to plan B.

if they dont blow listen for the click of the protect relay, and (if this model has one) the LED panel light changing from yellow to green.

still in protect with no click?
then go to planB

relay clicks and green light?
then switch off, reconnect the speakers carefully making sure that the cables or connections to them, both ends are not shorting.
play some music enjoy.


Plan B
get the amp fixed
as nigel said good possibility of blown output transistors and possibly a few more parts as well, hopefully only one channel

Plan C
this is the fun part, DIY or shop technician? see Plan B.

I MUST POINT OUT THAT I DO NOT RECCOMMEND THIS PROCEDURE FOR EVERY AMP WITH THIS PROBLEM.

regards
bob

[d7silver]

burbeck, yes I have test kit, just asking to see if anyone else had a similar problem in that all the fuses went. It is my sons amp and I doubt if it was under any load when it failed as him and his wife live in a small apartment and generally the noise is kept well down. I was just wanting to save time as I have enough things to fix. I also didn't want to waste 4 fuses....
Regards

[sakis]

nad has a history on blown trafos ...transfgormes are very marginal ...that might be a reason also, proceed with caution